It kinda slipped by, but synthetic oil would crank a lot easier. I am curious though, what would be the lightest oil for these in cold weather? That with the new battery and I would be surprised if it didn't start right off.

Probably one of the 5w synthetics like Castrol Power RS 5w40 or Motul 300V Ester 5W30.

I did manage to start the MC without too much cranks this morning; before starting I engaged and disengaged the clutch for around 10 times and then by pressing the clutch lever tried starting after around 2 or 3 cranks the engine came to life...It could be that the clutch is getting stuck when it is cold - because of the oil being think? I am not expert on this!Also, Do we periodically have to pour some oil in the left side case? I think this may not be required.But I still think it is something with the sprag clutch system (atleast in my MC) that is slipping the starter motor and not engaging the engine.BTW, I am using Mobil 1 V-twin SYN 20W-50; around 1.9L

Be sure you are using motorcycle oil, not car oil. The car oil can only do bad things to your engine. 10W40 or 50 should be fine. If it's staying cool throughout the day, 10W40 would probably be your best choice. It doesn't have to be synthetic, semi-synthetic would be fine. But, motorcycle oil.Bare

Also, Do we periodically have to pour some oil in the left side case? I think this may not be required.But I still think it is something with the sprag clutch system (atleast in my MC) that is slipping the starter motor and not engaging the engine.

If you have a UCE, you don't need to pour oil into it anywhere except the oil filler hole. The inside of the engine is basically one compartment, the oil goes everywhere. If you have an iron barrel or AVL, the gearbox, engine and primary case are different entities and should have different types of oil in each of them.This is why you don't run car oil, see above post, in motorcycles. The oil in a UCE has to handle three different lubrication jobs, where car oil only has to cover the engine. Modern car engines are designed for very low friction oils to get better mileage. The motorcycle bearings will not hold up to the lack of pressure resistance of these new oils. And guess what all this antifriction stuff does to clutches? STAY AWAY FROM CAR OILS.I'm omitting the truck oils, but I'll just say some of them are OK. They are old school oil that don't have the modern crap in them.But if you're not into oils, don't mess around. Stick with motorcycle oils. Bare

Moto oils are best for motos. Diesel specific oils are similar, they both have much more of the zinc and sulphur compounds (I think it's those anyway) that are good for cushioning gears in trannies and everything else as well. These have been minimized by law in modern car oils because they slowly erode the effectiveness of the catalytic converters and increase emmissions. If you do have to use car oil just make sure you get one that is NOT labeled as energy conserving. These have friction modifiers in them that can cause clutches to slip. Probably not a big issue with our modest hp but better safe than sorry.

I would say go full synthetic for two reasons. Air cooled engines run hotter than water cooled engines. Full synthetics resist breakdown at high temps better. Full synthetics also tend to flow better than conventional oils when it's cold, even for the same weight rating.

If the daytime highs aren't above 70 degrees F I would think you could go to a 10-40 wt with no problems at all.That's only 5 below the recommended low viscosity and the 50 in the 15-50 wt that is recommended is only useful for temperatures above 90.

I don't know if I would feel safe dropping to a 5-30. 5 weight oil is just about like water even when it's cool and its low viscosity could drop your oil pumps output pressure down to a dangerous low.

I had tried 10W-40 oil one winter season and engine started easier when temperature was between 20 to 55F. It may be OK to use if temperatures do not go above that throught day/night.

BUT I will not use it again even in NJ weather, because it is thin and light - it will not provide as much protection to engine when day time temperature rises to 60F or above. I am back to 15W-50 for all weathers and seasons of NJ.

Engine protection is far more important than small inconvenience of having to keep battery fully charged all the time. A good battery will start motorcycle in pretty cold temperature (mid 20F) without problem with 15W-50 oil.

Many good ideas have already been mentioned such as turning off headlight - very helpful. Using motorcycle synthetic oil - good idea, though semi-synthetic will do. Releasing clutch plates also helps. New or good clean spark plug - essential.

One more factor is gasoline quality. Try adding a little bit of Star Tron fuel additive to gas tank. I use it throughout winter and see noticeable improvement in starting in cold temperatures.

Hi All,Wanted to update on this topic from my side.Over the week I have been starting my 2011 C5 in the morning when the temperature has been around 40-46 F. What it seems as of now is, when I engage and disengage the clutch around 10 times or more and then disengage the clutch (by pressing the clutch lever) and at the same time engage the choke (or fuel enricher); the bike starts within 2 or 3 cranks.Couple of cranks before the bike fires up, I can hear the engine getting engaged by the starter motor. What I had found initially (without doing the above procedure) was starter motor would just keep spinning. When the bike is warm I can get is cranked up within 1 or 2 cranks, no problem there.

1. Does this still seem to be a sprag clutch getting weaker? - my dealer does think that is case.2. I have been only putting Mobile 1 V-twin syn 20w-50 moto oil into the oil hole on the RH crankcase.3. For UCE, even though there is no need to pour oil (same type as above) on the LH crankcase, would it help doing so? especially for cold start and what I am observing with the clutch plates having to be disengaged - again not sure this required...4. Could this be the auto-decompressor (?) needing adjustment, if any?

1. Does this still seem to be a sprag clutch getting weaker? - my dealer does think that is case. That is possible. Wear on the sprags from their slipping without fully engaging can damage the profile on the end of the individual sprags causing them to slip more.

3. For UCE, even though there is no need to pour oil (same type as above) on the LH crankcase, would it help doing so? especially for cold start and what I am observing with the clutch plates having to be disengaged - again not sure this required...There is no need to do this. The right and left sidecover both communicate with the central oil sump thru several holes.When the oil level is correctly filled, the oil in both sidecovers are at the proper level.

4. Could this be the auto-decompressor (?) needing adjustment, if any?The auto-decompressor is located on the exhaust cam and has nothing to do with the engagement of the sprag clutch. If it was not engaging, the starter motor would tend to 'bog down' as the piston rises on its first compression stroke but I don't think this would cause the clutch to slip more than it would with the auto-decompressor working right.

I haven't used either of these oils but going to the thinner 15-50 weight oil could help quite a bit.The sprags are usually located within a spring loaded device and the increased thickness of the cold 20-50 weight oil could cause them to 'hang up' on the springs rather than allowing them to freely engage the crankshaft as they should.The thinner 15 weight oil will be more like the warmed up 20-50 so I would expect the clutch to act more like the 20-50 does when the engine is warmed.

As for activating the clutch lever 10 times I can't see where this could have any effect on the starting problem.The clutch is on an entirely different shaft and its connection with the engines crankshaft (where the sprag clutch is located) is thru a duplex chain that won't transmit any horizontal movement of the clutch shaft to the crankshaft.Rather than doing this activating the clutch lever 10 times I suggest that before you try to start the engine you pull the clutch lever in and then push the kick starter lever down fully.The engine will not turn when you do this but the clutch plates will slide on each other breaking loose any stickiness they may have developed while sitting overnight.

Holding the clutch in while cranking the engine with the electric starter can reduce the additional drag of the transmission gears on the sprag clutch and starter motor

If it engages sporatically (on-off-on-off) then I'd say it's either the sprag or a low battery. If the starter just spins free for a bit and then it engages and stays engaged I'd say it's more likely a low battery. If there isn't enough torque from the starter motor (from a low battery or other problem) then the sprag with not engage properly.

I also agree that an oil with a lower W weight (10W, 15W) is a better option. The number before the W is the winter weight, or how the oil behaves when very cold. Thinner is better here, allowing the sprags to move freely and engage properly. Full synthetic is also better but it's tough to find 15W50 full syn in the US. I'd say 10W40 would be fine for the winter.

Thanks Arizoni and Ducati Scotty!Agreed, pulling the clutch lever 10 times will not have an effect on the starting problem. The reason I do this is because sometime (especially after the bike being parked for 2 or more days) when putting in first gear the bike sought of lurches forward, this can be avoided by pulling the clutch several time.The battery is 4 months old and is being put on battery tender when bike is not in use. The solenoid voltage is also good (did it according to singhg5's youtube video)I might try the 15W-50 after verifying the starting problem being less of an occurrence with the clutch lever pulled in.I am learning from you guys quite a bit...Again, thanks for the help! :-)

Dear Dallas Theologian, I have always found it beneficial to swear some when starting a stubborn engine, at least it eases the frustration. Are theologians allowed to do that? Automobiles, unlike motorcycles, have their own tin houses to protect engine & electrical componensts from the elements. Motorcycles, like Power Tools or Guns, should be kept indoors. You are simply going to have to move to a first floor apartment, or rent one with a garage/shed etc. if you want your Moto to last. At least Royal Enfields look nice in living rooms & dens.Craig McClure, Jasper Ga, USA